The proposed supplement is relevant to the ?Alzheimer's-focused administrative supplements for NIH grants that are not focused on Alzheimer's disease? because it will enhance our understanding of how to evaluate for Alzheimer's Disease and other related dementias in people with cochlear implants (CIs) ? bionic devices that partially restore hearing to people with moderate-to-profound hearing loss. Previous studies provide limited value in the general area of cognition in older CI users because of methodological limitations: (1) using cognitive measures with some degree of auditory demand; (2) using limited measurements and screeners in the clinic that are prone to inaccuracy; and (3) excluding participants with possible Alzheimer?s Disease (i.e., possible selection bias). This poor methodology has generated a clear gap in knowledge, where the mechanisms underlying poor cognitive performance in older CI users are unknown. The long-term goals of this supplement will move the current line of research to: 1) better understanding of the prevalence of cognitive impairment and Alzheimer's Disease in older CI users, 2) better understanding of the potential for CIs to diminish cognitive impairment and Alzheimer's Disease, and 3) development of appropriate evaluation tools for cognitive impairment and Alzheimer's Disease in older CI listeners by addressing potential sensory (hearing and vision) deficits. The short-term goals of this supplement are to create a team of hearing scientists (from the PI?s lab; experts in CIs, hearing, and aging) and medical professionals (experts in diagnosing Alzheimer's Disease and clinical audiology) to learn how neuropsychological evaluations are best performed in CI users, how our current hearing tests can be performed in CI users with cognitive impairment, and produce data that will be used for future grant applications on the topic. Our central hypothesis is aging and degradation of auditory input from the CI causes effortful speech understanding, which limit cognitive reserves and diminish cognitive abilities. We plan to test our central hypothesis via one specific aim: Determine how poor cognitive scores in older CI listeners are a result of clinically diagnosed age-related cognitive impairment, listening effort, and/or testing modality. Our expected outcome is that we will better understand the impacts of CI use on cognitive processing, cognitive decline, dementia, and Alzheimer?s Disease. This outcome is expected to have a significant positive impact as it will help uncover the mechanisms causing relatively poor cognitive and speech understanding performance in older CI users. Our successful results will provide guidance to clinicians to prevent, assess, and treat cognitive decline and Alzheimer?s Disease in CI users.